Zebrafish sensory hair cell regeneration

项目摘要 由毛细胞变性引起的听力损失是世界上最普遍的感觉障碍之一。 65岁至75岁的人中有30%受到影响。在人类和哺乳动物中，毛细胞不能 毛细胞会再生，因此毛细胞的任何损伤或丢失都是永久性的。因此，迫切需要 开发再生人类毛细胞的治疗方法。与哺乳动物不同，毛细胞在 鱼、鸟和两栖动物在毛细胞死亡后再生。我们对毛细胞为什么知道得很少 在一些脊椎动物中再生，而在其他脊椎动物中不能。这项工作的目的是阐明基因调控。 斑马鱼毛细胞再生的潜在网络，结果将帮助我们确定策略，以诱导 恢复哺乳动物失去的毛细胞。斑马鱼的耳朵和皮肤上有毛细胞，这是 感觉水运动的感觉侧线系统。斑马鱼侧线毛发的发育 细胞受与哺乳动物内耳毛细胞相同的信号通路控制，然而，它们很容易 可进行直接观察和基因操作。Notch和Wnt信号之间的相互作用是 对于维持祖细胞自我更新和分化之间的平衡至关重要。这项工作将会扩大 这一知识通过确定其他信号通路，如成纤维细胞生长因子和维甲酸(RA)，这也是 强有力地影响毛细胞再生，适合这个网络。The Notch，Wnt， 成纤维细胞生长因子和类风湿因子途径将通过使用突变体的途径的组合操作来确定， 药物抑制剂和转基因品系。此外，调节脑细胞平衡的基因相互作用 在体内，祖细胞的自我更新和分化将在单细胞水平上进行功能询问 时间推移和细胞增殖/细胞命运分析相结合。这项工作的一个重要组成部分是 单个支持细胞在再生过程中和通路操作后的表达分析。单曲 细胞分析是强大的，因为在支持细胞中发现了意想不到的多样性或嵌合体，这是 掩蔽在批量支持细胞RNAseq分析中。此外，当细胞分化时，它们将整合许多 随着时间的推移，来自其他细胞的不同信号。这些实验将允许在不同的细胞上区分 轨迹，按照这些轨迹在时间上对它们进行排序，并识别控制这些轨迹的新的监管因素 差异化。这些目标的结果将告诉我们斑马鱼毛发背后的基因调控网络。 细胞再生，这将指导设计诱导哺乳动物毛细胞再生的疗法。

Project Summary Hearing loss caused by hair cell degeneration is one of the most widespread sensory disabilities in the world with 30% of people between ages 65 -75 being affected. In humans and mammals, hair cells are unable to regenerate, hence any damage or loss of hair cells is permanent. Therefore, there is an urgent need to develop therapeutic approaches for regenerating hair cells in humans. In contrast to mammals, hair cells in fishes, birds and amphibians regenerate following hair cell death. Very little is known about why hair cells regenerate in some vertebrates and not in others. The goal of this work is to elucidate the gene regulatory network underlying zebrafish hair cell regeneration, The results will help us identify strategies to elicit the restoration of lost hair cells in mammals. Zebrafish possess hair cells in their ears and in their skin as part of the sensory lateral line system that senses water movement. The development of zebrafish lateral line hair cells is controlled by the same signaling pathways as mammalian inner ear hair cells, however, they are easily accessible to direct observation and genetic manipulation. Interactions between Notch and Wnt signaling are crucial for maintaining a balance between progenitor cell self-renewal and differentiation. This work will expand this knowledge by determining how other signaling pathways, such as Fgf and retinoic acid (RA), which also robustly affect hair cell regeneration, fit into this network. The epistatic relationship between the Notch, Wnt, Fgf and RA pathways will be determined by combinatorial manipulation of pathways using mutants, pharmaceutical inhibitors and transgenic lines. In addition, gene interactions that regulate the balance of progenitor cell self-renewal and differentiation will be functionally interrogated at the single cell level in vivo with a combination of time-lapse and cell proliferation/cell fate analyses. An important component of this work is the expression analysis of individual support cells during regeneration and after pathway manipulations. The single cell analysis is powerful, as an unexpected diversity or mosaicism in support cells was discovered, which is masked in bulk support cell RNASeq analyses. In addition, as cells differentiate they will integrate many different signals from other cells over time. These experiments will allow the distinction of cells on different trajectories, temporally order them along those trajectories, and identify new regulatory factors controlling differentiation. The results of these aims will inform us of the gene regulatory network underlying zebrafish hair cell regeneration, which will guide the design of therapies to induce hair cell regeneration in mammals.